216 A MANUAL Of THE CONIFERS. 



grow older, approach more and more nearly to a general type, in 

 which individual differences are too insignificant to call for a separate 

 designation. By far the most distinct of the varieties is the one above 

 described, of the origin of which nothing certain is known. 



Taxodium disticbum is a semi-aquatic tree, attaining its finest develope- 

 ment on the banks of rivers and amidst marshes and swamps, and is 

 nowhere met with at any distance from them. In those situations 

 the trunks attain an enormous diameter in comparison with the height; 

 the tallest known tree scarcely exceeds 120 feet in height, but many 

 have been met with whose circumferences have been found by measure- 

 ment to be 40 and 45 feet, or as much as one-third of the height ; 

 the circumferences of the largest "Wellingtonias are not greater than 

 one-fifth or one-sixth of their heights. Like the Sequoias, the trunks 

 of the deciduous Cypress swell out into large buttresses at the base, 

 but to such an excessive extent, that in order to fell the trees with 

 the smallest expenditure of labour, it is necessary to erect a stage at 

 from 5 to 6 feet from the ground. 



" The roots of large trees, particularly in situations subject to inun- 

 dations, become covered with conical protuberances, commonly from 

 18 inches to 2 feet high, and sometimes from 4 to 5 feet in thick- 

 ness ; they are always hollow, smooth on the surface, and covered 

 with a reddish bark like the roots, which they resemble, also in the 

 softness of their wood. No cause has been assigned for their existence, 

 they are peculiar to the deciduoiis Cypress, and begin to appear when 

 it is from 20 to 25 feet high. They are made use of by the negroes 

 of the Southern States for bee-hives.".* In England these protu- 

 berances or "-knees" are rare; at Syon House, the seat of the Duke 

 of Northumberland, where are some of the finest deciduous Cypresses 

 in Britain, "knees" have been produced, as is shown in the accom- 

 panying woodcut. 



The economic value of Taxodium distichum is very great throughout 

 the region in which it is abundant. This tree is to the inhabitants 

 of the Southern States what the Kedwood is to those on the- Pacific 

 coast of California, and it is used for much the same purposes. The 

 wood is light but strong, fine in grain, and splits easily into shingle 

 without the aid of a saw; it is of a reddish colour, of deeper hue 

 than the Virginian Eed Cedar, very durable, and almost imperishable 

 in water; it is much used for posts, fencing, railway sleepers, &c. 



The deciduous Cypress is quite hardy, and its great importance as 

 an ornamental tree in Great Britain is mainly due to two circum-, 

 stances, the peculiarly pleasing soft colour of its light feathery foliage, 

 combined with its graceful habit, and its adaptability for planting in 

 close proximity to water, and in damp places where few other Conifers 

 will live. It is, comparatively speaking, of rather slow growth, but 



* Loudon, Arl. et Frut., p. 2483. 



